Rotating rotary jar



Sept. 21 1926.

. c. E. THOMAS ROTATING ROTARY- JAR Filed July 22, 1925 2 Sheets-Shed 1 4 4 1 a4. Us! 3 x71; /,,---i i|.. 2 & 00 g 4 H W w 1 j v C. E. THOMAS ROTATING ROTARY JAR Filed July 22, 1925 2 Sheets-Sheet 2 i HII Sept. 21 1926. 1,600,744

A //1A A. VA. //A .nunnun.,...

Patented Sept. 21, 1926.

CHARLES E. THOMAS, OF LOS ANGELES, CALIFORNIA.

ROTATING ROTARY JAR.

Application filed July 22, 1925. Serial No. 45,217.

' Thisinvention relates to improvements in rotary jars used in well drilling operations, and in particular this invention is an improvement over the rotary jar disclosed in my prior Patent No. 1,540,436, issued June 2,

An object of this invention is to provide an improved means for holding the sleeve and mandrel of the jar in collapsed position whereby relative movement between these parts is prevented, such position being that in which the jar is normally disposed during drilling.

A further object of this invention is to 16 provide an improved rotary jar in which the mandrel and sleeve are held together in their normal position by means of threads, and to provide an indicating, means for indicating when the'threads on the mandrel and sleeve are disengaged, so that the drilling crew at the surface can ascertain at what time to apply an upward strain upon the drill tube. In this manner there willbe little or no occasion for prematurely applying the strain and thus stripping the threads.

With the foregoing and other objects 1n view which will be made manifestin the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a vertical section through the improved rotary jar, I

Fig. 2 is a sectional view through the sleeve showing the mandrel in elevation therein,

Fig. 3 is a side elevation of the mandrel, Fig. 4 is a vertical section through the sleeve,

Figs. 5, 6, 7, 8 and 9 are sectional views illustrating the operation of the improved rotary ar.

Referring to'the accompanying drawings wherein similar reference characters designate similar parts throughout, the improved rotary jar consists of a sleeve 10, on the upper end of which is mounted a coupllng member 11 for attachment to a drill tube. Within the sleeve 10 there is disposed a mandrel 12 having an axial bore 13 formed therein, and at the upper end of the mandrel 12 there is provided a head 14 from whlch depend bosses or projections 15. On the mandrel 12 below the projections 15 there are formed guide projections 16, the upper sur-' faces of which are downwardly inclined, as lndicated at 17 and the bottom surfaces of which are inclined as indicated, at 18. Upon the lnterior surface of the sleeve 10 there are formed projections 19 which slide upon the mandrel 12 and are capable of passing between the guide projections 16 and between the projections 15.

v The lower end of the mandrel 12 is enlarged, as at 20, and is exteriorly threaded, while the interior surface of the sleeve 10 below the projections 19 is correspondingly threaded so that the sleeve and mandrel may be screwed together. The lower end of the mandrel is provided with a pin 21 similar to a tool joint pin whereby the mandrel may be connected to a lower string of drillpipe or may have a tool attached thereto. The lower end of the sleeve 10 below the threads is adapted to seat upon a shoulder 22 formed upon the mandrel 12 and packing 23 may be compressed between the lower end of the sleeve 10 and the man'dreL, On the lower edge of the sleeve there is formed a shoulder or projection 24, and a complementary projection 25 is formed on the mandrel. Packing 26 is adapted to. be compressed against the top of the head 14 by means of nuts 27.

The operation of the jar is as follows: If the tool T becomes stuck in the bottom of the hole, the drill pipe Dis reversely rotated, causing the sleeve 10 to unscrew from the threads on the mandrel 12. After the threads on the sleeve and mandrel have been disengaged, the drill pipe D may be elevated, elevating the sleeve 10. The projections 19 pass between the guide projections 16 and may be guided so as to pass between them by means of the inclined surfaces 18. The guide projections are so arranged upon the mandrel as to be slightly offset from the projections 15, so that when the drill pipe D and the sleeve 10 are lifted, the projections 19 slide between the guide projections 16 and first encounter the lower ends of the bosses or projections 15. When the projections 19 have engaged the projections 15, an upward strain is placed upon the drill pipe sufficient to stretch it. In this position the drill pipe D is slightly rotated, so that the sleeve is rotated and the projections 19 slide off of the projections 15, striking the head 14. Fig. 7 shows the position in which the projections 19 are engaging the projections 15, while Fig. 8 shows the projections 19 as having struckthe head 14. In many cases one blow v or jar is sufficient to loosen the tool, but if for any reason this single blow is insufiicient to loosen the tool, the drill pipe D can be lowered a second time with the lower edges of the projections 19 encountering the inclined surfaces 17 on the guide projections 16. In sliding off of the inclined surfaces 17, the sleeve 10 and the drill pipe D are rotated slightly so that the projections 19 are again disposed between the guide projections 16. After this position is assumed, as shown in Fig. 9, the drill pipe D can again be raised and the projections 19 will again encounter the lower ends of the projections 15, from which position, which is similar to that shown in Fig. 7, a second jar may be produced upon the tool T. After the tool has been loosened, the drill pipe D and the sleeve 10 can again be lowered and screwed together. The purpose of the projections 24 and 25 isto prevent the sleeve 10 from screwing too tightly upon the mandrel 12, which might easily happen during the drilling operations and strip the threads or jam-the threads so tightly that it will be difficult to unscrew the sleeve from the mandrel.

In the preferred form of construction, the lower ends of the guide projections 16 are so arranged that when the sleeve 10 disengages from the last thread on the mandrel, the upper corners of the projections 19 will engage the lower corners of the guide projections 16. This will cause the rotation of the sleeve 10 and the drill pipe D to stop or hesitate so that the drilling crew on the surface can determine when the threads have been completely disengaged before attempting to lift the drill pipe and the sleeve. It is obvious that if the drill pipe and sleeve were lifted before the last thread was disengaged, this thread might easily become stripped. The above construction, wherein the projections 19'engage the guide projections 16, is diflicult to construct, however, and is not essential. The tool may be easily constructed by providing a predetermined 7 number of threads on the sleeve and the mandrel so that the drilling crew can reversely rotate the drill pipe a predetermined number of turns, and when the drill pipe has been so rotated,- they will then know that the threads have become disengaged. The bore 13 in the mandrel 12 provides for the discharge of circulation fluid through the tool and through the jar, so that the circulation fluid may be continuously pumped dur ing the drilling operations.

From the above it will be appreciated that an improved form of rotary jar is provided in which the sleeve and mandrel are held in their normal positions in an improved manner. It will be obvious, of course, thatthe jar does not have to be used in the position shown, as itcan be used in an advantageous manner it turned upside down. The particof the invention as defined by the appended claims.

I claim:

1. A rotary jar comprising a sleeve, 8. mandrel having a head formed thereon movable within the sleeve, means providing projections upon the mandrel adjacent the head,

means providing projections upon the interior of the sleeve, and guide means normally positioned between the projections on the sleeve and the projections adjacent the head for causing the projections on the sleeve to encounter the projections upon the mandrel upon separating movement of the sleeve and mandrel, whereby upon a part rotation of one of said parts, the' projections on the sleeve may disengage the projections on the mandrel and be caused to strike the head.

2. A rotary jar comprising a sleeve, 8. mandrel slidable within the sleeve havin a head provided thereon, means providlng projections on the mandrel adjacent said head, means providing projections upon the interior of the sleeve, and means providing guide projections upon mandrel which are normally located between the projections on the sleeve and the projections on the mandrel, said guide projections being so arranged that upon separating movement of the mandrel and sleeve, the projections on the sleeve may be engaged thereby and guided to engage the projections on the mandrel before engaging the head.

3. A rotary jar comprising asleeve, a mandrel slidable within the sleeve having a head provided thereon, means providing'projections on the mandrel adjacent said head, means providing projections upon the inte- Iior of the sleeve, and means providing guide projections upon the mandrel which are normally located between the projections: on the sleeve and the projections on the mandrel, said guide projections being so arranged that upon separating movement of the mandrel and sleeve. the projections on the sleeve. may

be engaged thereby and guided to engage the projections on the mandrel before engaging the head, the edges of the guide projections adjacent the projections on the head being inclined as and for the purpose described.

4. A rotary jar comprising a sleeve. a: mandrel disposed within the sleeve and slidable therein, means providing a head upon the the mandrel, means providing projections upon the mandrel adjacent said head, means providing projections upon the interior of the sleeve, there being threads formed upon 6 the mandrel and sleeve adapted to engage to prevent relative movement between the sleeve and mandrel, and guide means whereby upon disengagement of the threads the projections on the sleeve may be guided so as to encounter the projections upon the mandrel 10 before striking said head.

In testimony whereof I have signed my name to this specification.

CHAS. E. THOMAS. 

